In the Tang Dynasty, Princess Taiping had a dream of riding a "silver snow white horse" galloping under the moonlight in a "fairyland". The female Taoist Xuan Ji interpreted her dream and said that the white horse was a "heavenly horse". She made the princess's "dream come true". Xuan Ji was favored. At this time, the great detective Di Renjie of the Tang Dynasty solved a "family extermination case", but it turned out to be a life tragedy caused by the "heavenly horse".